Clamping device



p 1952 G. R. ANDERSON 3,055,068-

CLAMPING DEVICE Filed May 26, 1960 24 5a 4e 52 so 54- 40 "WW i l? INVENTOR. 40 ioaizn4/vaiiim United States Patent O 3,055,068 CLAMPING DEVICE George Robert Anderson, Topanga, Calif. Filed May 26, 1960, Ser. No. 31,991 3 Claims. (Cl. 2481) This invention relates to an instrument mounting device, and has particular reference to a clamp type mounting device arranged to provide a means for releasably clamping an elongated instrument.

Various forms of clamp type mounting devices are known in the prior art, but none of them, within the knowledge of the present inventor, are free from certain material disadvantages which this invention has been particularly conceived to overcome.

One usual form of a clamp type mounting device comprises a band having end portions in overlapping relationship. The instrument is placed within the band so that it is circumscribed thereby and is clamped by operation of a mechanism such as a screw, to reduce the circumference of the band, until the instrument is tightly secured. This type of device has certain disadvantages which makes its use impractical, if not inoperative, where it is necessary to mount elongated instruments in a relatively small, confined space.

To secure an instrument having an elongated chassis, such as a radar oscilloscope, it is necessary, for support of the chassis, that it be clamped and secured to the structure at several points along its length. Heretofore, a multiple of single clamps, as described above, were used. However this necessitates that the technician mounting the instrument be able to operate the securing mechanism from a position on one side of the clamp. Therefore, When the instrument was mounted in a relatively small confined area, such as the area adjacent to the instrument panel in an airplane cockpit, it was difficult for the technician to operate the clamps. In addition, if for some reason it was necessary for the operator to remove the instrument during operation of the airplane, the removal of the instrument was found to be practically impossible because of the congestion in the cockpit during flight operations.

The present invention is designed to provide a clamp type mounting device for mounting with ease and efficiency, within a relatively small and confined area, instruments having elongated chassis. This end is accomplished by providing a securing mechanism which is operable to secure a pai of clamps from a position adjacent to the face or front of the instrument.

Briefly, the present invention comprises: dual strap members, each of said members having a free end portion adapted to be urged toward each other; two pivot plates for urging the said end portions of both strap members together simultaneously, each of said pivot plates being pivotally attached to the free end portions of one of said strap members and both being joined by a spreader bar for simultaneous movement, and an actuating screw for rotating the pivot plates, drawing the end portions of the straps together in an overlapping relationship and tightening the said straps about the object being supported.

In the accompanying drawing there is illustrated what is now considered to be the preferred embodiment of the idea of the invention. The drawing, however, is for the purpose of illustration only and is not to be taken as limiting the invention. The scope of the present invention is to be measured entirely by the scope of the appended claims.

In the drawing is shoWn a perspective view of the present invention mounted to a section of rigid or fixed structure. In addition, there is shown as represented by 3,055,068 Patented Sept. 25, 1962 ice a series of dotted lines, the instrument contained and secured by the present invention.

Referring to the drawing in detail, the numeral 10 represents the rigid or fixed structure to which the present invention is secured by conventional brackets and shock mounts 12. Wll'lllC the invention is shown mounted by brackets and shock mounts, the invention is not intended to be limited solely to such applications. The present invention is adaptable fo many uses and can be mounted in a variety of modes, of which, the present drawing depicts but one.

Secured to the brackets 12 is the lower portion 14 of similar first and second elongated strap members 15, 16 respectively. As shown in the drawing and described hereinafter, the elongated strap members define a rectangular shape or area. While in the presently preferred embodiment of this invention, the inventor has chosen to contour the strap for mounting rectangular or square shaped instrument chassis, it will be apparent from the following description that the straps can be contoured to define any shape within the scope and essence of the invention.

The elongated strap member comprises, in addition to lower portion 14, first and second side portions 18, 20 respectively, and correspondingly, first and second free end portions 22, 24. The first and second side portions 18, 20 respectively comprise: lower parts 26, 28 respectively, intermediate parts 30, 32 respectively, and upper parts 34, 36 respectively.

The longitudinal axes of the respective parts of each side portion define parallel longitudinal planes. The longitudinal axes of the lower parts 26, 28 are coplanar with a transverse plane containing the longitudinal axis of the lower portion 14. The longitudinal axes of the upper parts 34, 36 are parallel with the transverse plane containing the longitudinal axis of the lower parts 26, 28 but on opposite sides thereof. The longitudinal axis of the intermediate parts 30, 32 are inclined approximately 10 with respect to the transverse plane and are directed in opposite direction therefrom.

To complete the enclosure of the strap about the chassis, the free end portions 22, 24 are contoured in a plane substantially parallel with the plane of the upper surface or top of the chassis. However, because of the inclination of the corresponding intermediate parts 30, 32 of the sides 18, 20, the free end portions 22, 24 do not close on each other but are in an adjacent overlapping relationship.

To form the preferred embodiment of the present invention, the second elongated strap 16 is secured to the structure parallel to the first strap 15, but in a reverse orientation. That is, the first side portion 18 and the second side portion 20 of the second strap 16 are respectively coplanar with the corresponding second side portion 20 and the first side portion 18 of the first strap 15.

The end portions 22, 24 of the strap members 15, 16 are pivotally attached by conventional means, such as rivets, to two adjacent vertices of first and second triangular pivot plates 38, 40 respectively. Attached to the third vertex of the first pivot plate 38 is a flanged member 42. Said member projects upward from the side of the plate opposite the side to which the end portion is attached; and contains an aperture and coaxially thereof a conventional nut plate 44.

The second triangular pivot plate 40 includes a pro jected portion 46 and aperture therein. Inserted in said apertures for containment therein is an elongated actuating shaft member 48. Said shaft member is threaded at one end to enable it to be threaded into the nut plate 44.

Adjacent to the end 50 and coaxial with said shaft are washers 54, 56 and located between them is a spring member 52. Said spring member 52 bears against said washer 54, which is fixed in position and serves as an abutment, and also presses against washer 56 which in turn bears against the projected portion 46 of the second triangular plate 40. Pinned to the shaft, in the region between the flange member 42 and the projected portion 46 are first and second stops 58 and 59 respectively. These stops are so spaced that they will prevent the shaft from excess displacement fore and aft of the nut plate 44.

To provide a concurrent clamping of both of the straps a spreader bar 60 is secured to adjacent corners of the pivot plates 40, 42, and a pair of stifieners are secured to adjacent intermediate parts 30, 32 of the side portions 18, 20 respectively.

The operation of the mechanism is as follows: upon counterclockwise rotation of the shaft 48, by insertion of mechanical means, such as a screw driver, into the slot in the end 50, until the first stop 58 bears against the projected portion 46, the strap members 15, 16 have been opened sulficiently to allow the insertion of an instrument chassis into the area enclosed by the straps. When the chassis is properly oriented in a fore and aft direction so that it is enclosed by both strap members 15, 16, the shaft is rotated in a clockwise direction to securely clamp the chassis. The clockwise rotation of the shaft applies a force to the first pivot plate 38 by the advancing of the threaded portion of the shaft 48 in the nut plate 44. This simultaneously applies a force to the second pivot plate 40 by the transmission of the force through the spreader bar 60. The force applied to the pivot plates results in a tangential displacement of the free end portions 22, 24 and a general tightening in a peripheral sense of the strap members 15, 16.

As the straps are tightened, the spring member 52 is compressed and provides an equalization of the clamping force between the two straps. To maintain the clamping force Within safe limits, the rotation of the shaft becomes increasingly diflicult as the spring is compressed until the shaft has been advanced through the nut plate sufficiently for the second stop 59 to make contact with the flange member 42 on the first pivot plate 38. In a like fashion, to release the chassis, the shaft is rotated in a counterclockwise direction until the first stop 58 is in contact with the flange portion of the second plate, whereupon the straps have been opened peripherally and the chassis is freed and can be removed from the device.

Various modifications are contemplated and may obviously be resorted to by those skilled in the art without departing from the spirit and scope of the invention, as hereinafter defined by the appended claims, as only a preferred embodiment thereof has been disclosed.

I claim:

1. A clamping means comprising: dual strap members adapted to encircle an object, each of said members having free end portions adapted to be urged toward each other; means for urging the said end portions of both strap members together simultaneously, said means comprising: a pai of pivot plates, each pivotally attached to the free end portions of one of the strap members, a spreader bar attached to said pivot plates adapted to produce simultaneous movement thereof; and an actuating screw associated with said pivot plates for rotation thereof; whereby said end portions are drawn together in an overlapping relationship to tighten the said straps about the object being clamped.

2. A clamping device comprising: dual strap members having overlapping end portions adapted to be urged toward each other; a pair of pivot plates, each pivotally attached to the overlapping end portions of one of the dual strap members for urging said portions together; a spreader bar attached to said pivot plates; rotatable means coacting with said pivot plates for rotation thereof, whereby said end portions are displaced tangentially to peripherally displace said dual strap members, and means limiting the extent of motion of the last said means.

3. A clamping device comprising: dual strap members adapted to encircle an object, each having free end portions adapted to be urged toward each other; means for urg'ing'said end portions together simultaneously, said means comprising: a pair of pivot plates, each pivotally attached to the free end portions of each one of said strap members, a spreader bar attached to said pivot plates; an actuating screw associated with said pivot plates and adapted to produce rotation thereof; and rotation resistive means adapted to prevent excess rotation of said pivot plates, said means including a spring and plurality of stops circumscribing said actuating screw; whereby said end portions are drawn together in an overlapping relationship to safely tighten said straps about the object being clamped.

References Cited in the file of this patent UNITED STATES PATENTS 203,444 Hall May '7, 1878 1,422,779 Perony July 11, 1922 2,277,738 Wilkinson Mar. 31, 1942 2,541,206 Christophersen Feb. 13, 1951 

